Liquid flow valve system

ABSTRACT

A system of distributing liquid flow to either a primary outlet opening or a secondary outlet opening. Each outlet opening has a valve for opening and closing a fluid passage thereto, the two outlet valves being mechanically connected so that when one is open the other is closed. The two mechanically connected valves are ordinarily resiliently urged so that the primary outlet opening is closed and the secondary outlet opening is open to allow fluid to flow therethrough. When the primary outlet opening is open to the atmosphere in order to obtain a liquid flow therefrom, the valve assembly moves under fluid pressure to open the primary outlet and close the secondary outlet. One application of this assembly disclosed herein is for a portable pumping assembly wherein the secondary outlet opening serves as a liquid bypass to the inlet of the pump when a liquid flow through the primary outlet opening is not desired.

3,827,827 Aug. 6, 1974 LIQUID FLOW VALVE SYSTEM Raymond Roger Hill, 11 White Cottage Rd., Angwin, Calif. 94508 Filed: July 6, 1972 Appl. No.: 269,494

Inventor:

References Cited UNITED STATES PATENTS Primary Examiner-Carlton R. Croyle Assistant Examiner-Richard Sher Attorney, Agent, or FirmLimbach, Limbach & Sutton 5 7] ABSTRACT A system of distributing liquid flow to either a primary outlet opening or a secondary outlet opening. Each outlet opening has a valve for opening and closing a fluid passage thereto, the two outlet valves being mechanically connected so that when one is open the other is closed. The two mechanically connected valves are ordinarily resiliently urged so that the primary outlet opening is closed and the secondary outlet opening is open to allow fluid to flow therethrough. When the primary outlet opening is open to the atmosphere in order to obtain a liquid flow therefrom, the

valve assembly moves under fluid pressure to open the primary outlet and close the secondary outlet. One application of this assembly disclosed herein is for a portable pumping assembly wherein the secondary outlet opening serves as a liquid bypass to the inlet of the I pump when a liquid flow through the primary outlet opening is not desired.

14 Claims, 4 Drawing Figures LIQUID FLOW VALVE SYSTEM BACKGROUND OF THE INVENTION This invention is related generally to valves and more particularly a valve system for controlling fluid flow under pressure between two independent paths.

A primary use of the valve assembly according to the various aspects of the present invention is in conjunction with a continuously powered liquid pump wherein an intermittent delivery of liquid under pressure is desired. An example of such existing systems is a portable or semi-portable pumping system that includes a liquid reservoir having two hoses connected therewith, one hose for extracting liquid from the reservoir and another one for discharging liquid from the output of the pump back into the reservoir. Such a discharge into the reservoir serves as a bypass and occurs when no liquid is desired from the pump. When the pump outlet hose nozzle is actuated to cause a liquid flow therethrough, liquid is no longer fed back to the reservoir. The bypass flow to the reservoir is required because the pump is continuously operating and must therefore continuously pump liquid even though none is desired through the outlet hose.

A problem in such systems where true portability of the pump and reservoir is desired is that two hoses between the pump unit and the reservoir are heavy and cumbersome. The bypass hose may be eliminated if some means are provided for feeding the output of the pump directly back to its inlet opening during those periods when no liquid discharge through the outlet nozzle is desired. This direct bypass is suggested by U.S. Pat. No. 3,103,891 Fulton et al. (1963). A bypass path is provided with a valve that is resiliently urged to its closed position. The fluid control assembly shown by this patent suffers from certain disadvantages including a mechanical complexity, slow response when liquid is demanded from its output and possible damage when the reservoir of liquid runs dry.

Accordingly, it is a primary object of the present invention to provide a liquid flow control system that responds quickly to a demand from a remote nozzle for a flow of liquid under pressure.

It is another object of the present invention to provide a pump unit with a valve system that results in low energy consumption by a pump driving motorand that also prolongs motor life.

It is a further object of the present invention to provide a liquid flow control assembly that is mechanically simple.

It is yet another object of the present invention to provide a liquid valve system which may be employed in a portable pumping 'unit of lightweight and improved flexibility.

SUMMARY OF THE INVENTION These and additional objects of the present invention are accomplished by a valve system wherein an inlet of liquid under pressure is divided into primary and secondary liquid flow paths, each being equipped with a valve movable between open and closed positions. When liquid is demanded from the primary liquid path by opening it to atmosphere either adjacent the valve system or a remote location therefrom, the primary path will move from a resiliently held closed position to an open position to allow flow therethrough, The valve in the secondary liquid flow path is mechanically connected to the primary valve in a manner that the secondary valve is closed when the primary valve is open, and vice versa. Therefore, absent a demand for liquid through the primary path, liquid will flow from the inlet to the assembly through the secondary liquid flow path. The secondary liquid flow is interrupted as the primary valve closes when liquid is demanded from the primary liquid flow path.

Such a valve assembly has a particularly useful application in combination with a continuously operating liquid pump. When the primary valve is open, the pump discharges liquid under pressure into the primary liquid flow path from a liquid reservoir which is connected to the pump inlet. When the primary flow path is blocked in some manner, such as by closing a nozzle at the end of a hose, the primary valve is moved by a resilient urging thereagainst to its closed position. With this movement, the secondary valve is pulled open. The secondary liquid path is connected directly back to the pump inlet to form a bypass path through which liquid continues to flow when liquid is not desired from the primary flow path. The pump is driven by some motor source, such as a small internal combustion engine, which is throttled down to a low speed when the valve is in its bypass condition by means of a mechanical connection between the motors carburetor and the moving valve assembly. An adjustable orifice is provided in the secondary or bypass liquid path for controlling the pressure of liquid when the valve is in the bypass condition. Also, a normally closed spring-held check valve is provided in the bypass or secondary liquid flow path in order to prevent circulation therethrough of air when the pump is first started, thus facilitating pump priming.

There are many advantages to the particular valve system of the present invention, especially when used with a pump to form a complete pumping unit. One advantage is that only one hydraulic line is necessary from the pumping unit to a reservoir, thus making the pumping unit lighter and less cumbersome for portable use. Another important advantage is the pump simplicity, employing one primary moving part which forms valves in two independent flow paths. Since the bypass or secondary valve is resiliently held open, damage to the pump driving motor is prevented if the liquid reservoir should run out of water. Under this condition, the bypass valve opens and through its mechanical linkage with the driving motor will idle down the motor. The simple pump driving motor speed control increases engine life by slowing down the motor during periods when liquid is not desired through the primary flow path. Additionally, fuel consumption by the motor and engine heat are also reduced. Also, carbon build-up in an internal combustion engine is reduced by its intermittent operation which corresponds with the intermittent demand for liquid under pressure.

The adjustable orifice in the bypass or secondary fluid path allows maintaining a high pressure in the primary path upstream of its valve so that when liquid is demanded by opening the output of the primary fluid path to atmosphere, a quick response of the valve system and establishment of liquid under pressure in the primary liquid path results. To assure quick action of the valve assembly when liquid is demanded from the primary fluid path, theprimary and secondary (bypass) valves cooperate with their respective valve seats so that as the primary valve is just beginning to open, the secondary (bypass) valve is just beginning to close. This sends a sudden shock wave of liquid pressure against the primary valve through the primary fluid path to quickly open that valve and thereby to quickly close the secondary (bypass) valve. The valve assembly is designed so that substantially no liquid needs to be displaced before the valve can operate, thus improving its quick response.

An application of the pump unit including a pump, motor and improved valve assembly combination is in a backpack fire fighting pump wherein the liquid reservoir may be a bag carried by a second member of the fire fighting team or could be a barrel or liquid stream from which water is pumped. In this application, dependability and quick response are requirements that the improved valve assembly of the present invention uniquely satisfy.

Another possible application of the valve assembly alone without a pump or driving motor is in a house water supply system wherein the primary liquid passage is connected to the house plumbing circuits and the secondary liquid passage is connected to something that needs a great deal of water, such as a garden. Water will flow to the garden from a source of liquid under pressure at all times escept when water is demanded in the house, such as by the opening of a faucet. When water is demanded in the house, it will be immediately diverted thereto while the secondary liquid path is shut off by closing of the secondary valve.

Additional objects and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment thereof which should be taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view, partially schematic, of an embodiment of the improved valve assembly according to the present invention in combination with a motor driven pump;

FIG. 2 is a side view of a portion of the valve assembly of FIG. 1 taken across section 22 thereof;

FIG. 3 shows a portion of the valve assembly of FIG. 1 in a transition position; and

FIG. 4 shows a portion of the valve assembly of FIG. 1 in yet another position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the improved valve assembly of the present invention is shown in a specific embodiment thereof. A casing 11 is shown in a cut-away view so that the internal operating parts may be observed. Attached to the valve casing 11 by some convenient means (not shown) is a pump casing 13 having a positive displacement vane pump 15 therein that is rotated by some convenient motor source shown schematically by block 17. In a very specific embodiment, the motor source 17 is an internal combustion gasoline motor. Liquid is drawn by the pump through its pump intake port 19 and discharged through a pump discharge port 21.

A liquid reservoir 23 is shown schematically in FIG. 1 as a supply of liquid for the pump and valve assembly which is drawn by the pump through a liquid inlet 25 of the valve casing 11 from an inlet hose 27 that contacts the liquid held by the reservoir 23. The reservoir 23 may be a portable water bag, as mentioned previously, when the pump and valve assembly is in a portable form or the reservoir 23 might be any convenient source of water or other liquid that is desired to be pumped.

A hand-held outlet nozzle 29 is provided for discharging pump liquid and contains a shut-off valve therein that is easily hand operated. The nozzle assembly 29 is connected by a hose 3] to a primary outlet opening 33 of the pump casing 11. The valves and pump system shown in FIG. 1 operates with the vane pump 15 being continuously driven by the motor source 17. When the valve is opened in the nozzle assembly 23, liquid is pumped from the pump discharge port 21 through the hose 31 and out the end of the nozzle assembly 29. When the outlet valve and the nozzle assembly 29 is shut, liquid flows through a secondary or bypass path from the discharge port 21 of the pump and back to the pump inlet port 19. During the time that liquid is not being discharged from the nozzle assembly 29, no liquid is being removed from the liquid reservoir 23.

The construction and operation of the valve assembly within the valve casing 11 which performs this bypass function in response to the nozzle 29 being closed off or opened will now be explained. A liquid source channel 35 within the casing 11 is connected to the discharge port 21 of the pump assembly. Connected to the liquid source channel 35 are two possible paths which the liquid under pressure may take. The first path is a primary liquid passage 37 which communicates the pump outlet to the primary outlet opening 33 and on to the nozzle 29. The second path is through a secondary (bypass) passage 39 which communicates the pump outlet flow back to its intake port 19 when this secondary path is open.

Each of the primary and secondary paths includes a valve which is connected together by means of a rod 41. A flange 43 is rigidly attached to the rod 41 within the primary discharge path and thus serves as a primary outlet valve. The rod 41 passes between the primary and secondary passages through a wall structure 45 of the casing 11 that separates the two passages. An end 47 of the rod 41 serves as the valve in the secondary (bypass) passage 39. The opposite end of the rod 41 passes through an end plug 49 held by the casing 11. The end of the rod 41 outside the casing 11 is connected rigidly to a bar 51. A spring 53 held under compression between the bar 51 and the plug 49 normally urges the rod 41 in a direction to open the secondary or bypass passage 39 and close the primary liquid discharge passage 37.

FIG. 1 shows the rod 41 in its normal position as urged by the spring 53 with no flow to the nozzle assembly 29 and the pump flow through discharge port 21 is being passed directly back to the pump intake port 19. As part of the bypass passage 39, a check valve assembly is provided that includes a movable valve member 55 and a valve seat 57 that is attached to the casing 11. A spring 59 normally holds the movable valve member 55 in a position to close off flow through the bypass passage 39. However, when the bypass passage is otherwise open and flow through the primary flow passage 37 is cut off, the movable valve member 55 is urged by liquid pressure against its spring 59 to is to prevent recycling of air when the pump is first started in operation. Pump priming is thus facilitated.

The primary valve flange 43 is positioned with the sides of the primary fluid passage 37 serving as a valve seat. The valve seat is a fluid passage portion that joins two parallel but offset portions 37 and the portion terminating in the outlet opening 33. This double right angle bend in the outlet passage is provided for this valve so that a straight rod 41 to which it is connected may extend directly into the secondary flow passage 39 which is generally parallel to the major portions of the primary flow path 37. The valve flange 43 is not required to shut off liquid flow to the nozzle 29 since the nozzle assembly 29 has its own shut-off valve that is operable by the user of the pump, but rather the valve flange 43 is provided for actuating the rod 41. It will be noted from FIG. 4 that when the valve in the nozzle assembly 29 is open to permit liquid discharge therethrough, the rod 41 has been urged against the spring 53 to its second extreme position wherein the valve flange 43 no longer closes off the primary liquid path 37 and permits liquid flow to the nozzle assembly 23. At the same time, the bypass valve 47 has been lodged into its valve seat 61 which closes off liquid flow through the secondary (bypass) passage 39. It will further be noticed that the cross-sectional diameter of the rod 41 is much smaller than the large dimensions of the primary liquid passage 37 so that it will not significantly obstruct flow therethrough. Since the bypass passage does not need to have as much flow capability, the small end 47 of the rod 41 serves quite satisfactorily as the bypass passage valve.

Referring to FIG. 2, a portion of the secondary (bypass) passage is shown which connects a cylindrical portion 61, that serves as a seat for the bypass valve 41, with the intake port 19 of the pump assembly. In this bypass passage, an adjustable orifice 63 is made possible by a restrictive rod 65 that is threadedly engaged with a portion 67 of the valve casing 11. When the member 65 is rotated, the size of the orifice 63 is adjusted. The purpose of the adjustment of the bypass path as shown in FIG. 2 is to permit adjustment of the liquid pressure in the liquid source channel 35 and the primary liquid passage 37. A high liquid pressure is desired when the valve assembly is in its bypass state as shown in FIG. 1. The pressure may be monitored by a pressure valve 69 that communicates with these liquid channels. The reason for this high pressure is to provide for fast action movement of the rod 41 when the outlet valve in the nozzle 29 is opened so that liquid may be diverted from the bypass path to the nozzle assembly 29 almost immediately after it is demanded by the operator.

The structure responsible for rapid valve action in response to the nozzle 29 being opened may be noted by following action of the rod 41 as it changes from its bypass flow state to its nozzle flow state. Referring to FIG. 3, the rod 41 is shown in an intermediate position immediately after liquid is demanded by an operator 2ho has opened the valve in the nozzle assembly 29. By opening this valve, the downstream section of the flange 43 is at atmospheric pressure while upstream is uid pressure at this time forces the flange 43 and its attached rod 41 downward. Just as the flange 43 is about to open the primary liquid flow passage and allow liquid to pass to the nozzle 29, the bypass valve 47 is just beginning to seat in its valve seat 61 and close off the bypass flow passage. (FIG. 3) When this occurs, there is a surge or shock wave of liquid which travels through the primary liquid passage 37 and against the upstream side of the flange 43. This surge drives the rod 41 quickly and with great force downward until it is in its extreme position shown in FIG. 4. Liquid then flows out to the nozzle 29 and the bypass passage is shut off. When the nozzle assembly valve is again shut off, the liquid forces acting on the flange valve 43 are substantially equalized and thus the force of the spring 53 returns the rod 41 to its bypass condition shown in FIG. 1. Also aiding in this movement to the position of FIG. 1 is a liquid force acting upon the valve surface 47 in the bypass passage. As the bypass passage is first opened, liquid flow therethrough tends to exert an upward force on the rod 41 to aid the spring 53 in returning it to its position shown in FIG. 1. The valve assembly remains in the position shown in FIG. 1 until an operator again opens the outlet valve in the nozzle assembly 29.

Movement of the valve rod 41 also affects the motor 17. A throttle wire 71 passes loosely through an opening 73 of the bar 51 that is rigidly attached to the rod 41. A throttle wire stop 75 is attached to one end of the throttle wire 71. The throttle wire 71 is connected with the motor 17 in a manner that when it is drawn outward away from the motor in the manner shown in FIG. 1, the speed of the motor 17 is reduced. Thus, when the valve assembly is in its bypass condition, the motor 17 is throttled down, thus saving fuel and extending its life and reducing maintenance thereon. When the valve 41 is operated to close the bypass passage and open the primary flow passage to the nozzle 29, as shown in FIG. 4, the throttle wire is permitted to travel downward therewith. The bar 51 does not pull the throttle wire 71 but merely provides an adjustable stop. In the case of FIG. 1, the throttle wire 71 is permitted to travel downward a very limited distance, while in the condition of FIG. 4, the throttle wire 71 is permitted to travel downward a further distance to permit the motor 17 to increase its speed for discharging liquid from the nozzle 29. I

The valve assembly of the present invention has been described with respect to a compact self-contained pump unit which may be, for instance, used as a backpack fire pump for forest fires. There are many other applications for the valve assembly according to the present invention, either as it is described with respect to the drawings or with certain modifications thereof. For instance, the secondary passage 39 need not be bypassed back to the intake port 19 of the pump but rather could be diverted to form a second liquid output by connection of a second outlet to the secondary flow portion indicated at 61. Thus, the pump would be drawing liquid from the reservoir 23 at all times and because of the valve assembly would be discharging liquid either through the primary outlet 33 or this new secondary outlet. Liquid would normally be flowing through the new secondary outlet until liquid was demanded by opening a valve in the primary outlet. The valve assembly including the rod 41 would then operate as a means to immediately divert liquid upon demand to the primary outlet 33 when the valve 43 is open while providing for a continuous flow at all other times through the new secondary outlet. in such a use, the construction of the valve assembly may desirably be additionally altered by placing the spring 53 within the casing 11 and not extending the rod 41 out of the casing. This can be done since no throttle attachment would be utilized. Such a valve assembly could be used with, for instance, a municipal water supply or it could be used with a well having a pump driven in a continuous speed at all times.

A preferred pump for use in the embodiments described with respect to the drawings includes a third passage (not shown) within the pump casing 13 connecting the discharge port 21 back to the intake port 19. This third passage includes a relief valve that allows liquid bypass when the pump outlet pressure reaches some preset high level. The third passage and relief valve are desirable for safety by determining the maximum pump outlet pressure that is permitted. This relief valve will open for a short time immediately after the nozzle assembly 29 is shut off since both primary and secondary passages are then temporarily closed by an intermediate position of the rod 41. This relief valve also permits use of very small outlet orifices on the nozzle assembly 29. if such a relief valve is not provided as part of the pump within the casing 13, it should be provided in the valve casing 11.

The various aspects of the present invention have been described with respect to its preferred embodiments, but it will be understood that the invention is entitled to protection within the full scope of the appended claims.

I claim:

1. A liquid pumping assembly, comprising:

a pump having intake and discharge ports,

means adapting said intake port for drawing liquid from a liquid source,

a discharge liquid path in fluid communication with the discharge port of said pump and with an outlet adapted for connection of a liquid discharge hose, said discharge path including a valve operable between open and closed positions,

a bypass liquid path in fluid communication from the discharge port of said pump to its intake port, said bypass path including a bypass valve operable between open and closed positions,

mechanical means connecting said discharge and bypass valves for operating said valves as one unit, said discharge valve being open only while said bypass valve is closed, and, conversely, said discharge valve being closed only while said bypass valve is open, said mechanical operating means additionally controlling the discharge and bypass valves in a manner that when said discharge valve is initially opened said bypass valve is simultaneously closed, thereby to create a rapid liquid pressure increase in the liquid discharge path that quickly drives the discharge valve fully open.

2. A liquid pumping assembly according to claim 1 which additionally comprises means associated with said mechanical connecting means for resilient biasing said discharge valve to a closed position and thus to bias said bypass valve to an open position.

3. A liquid pumping assembly according to claim 2 which additionally comprises a liquid hose attached to said discharge outlet, and a valve installed on said hose that is operable between open and closed positions, whereby opening said hose valve to the atmosphere causes said discharge valve to move to its open position while the bypass valve moves to its closed position.

4. A liquid pumping assembly according to claim 1 wherein said mechanical connecting means includes a rod extending between said liquid discharge path and said liquid bypass path, one end of said rod located within the bypass path forming said bypass valve and an enlarged flange surrounding said rod within said discharge liquid path forming said discharge valve.

5. A liquid pumping assembly according to claim 1 which additionally comprises a motor operably connected for driving said pump, said motor having a speed control regulator that is operably connected with said mechanical connecting means in a manner to drive said motor at a low speed when said bypass valve is in an open position.

6. A liquid pumping assembly according to claim 1 wherein said bypass liquid path includes means for controlling the size of said passage, thereby to permit control of liquid pressure against said discharge valve when in its closed position, whereby the speed of response of said valve moving to its open position may be controlled.

7. A liquid pumping assembly according to claim 3 wherein said bypass liquid path includes a normally closed check valve which opens upon fluid pressure therein reaching a certain threshold value above normal atmospheric pressure, whereby pump priming is facilitated.

8. A liquid pumping assembly, comprising:

a housing,

a liquid receiving inlet to said housing,

a primary liquid passage within said housing forming at least one sharp turn of substantially between said liquid inlet and a primary liquid outlet openmg,

a flange the size of said primary liquid passage and attached to a rod having a diameter significantly less than the size of said primary liquid passage for moving with said flange between extreme positions of closing said primary liquid passage by engaging all sides thereof and opening said primary liquid passage by moving to a position in said substantially right angle turn that allows fluid to travel along said primary liquid passage around said turn,

a secondary liquid passage within said housing and in fluid communication with said liquid receiving inlet for discharging liquid through a secondary openmg,

said rod extending out of said primary liquid passage through a liquid-tight opening therewith, one end of said rod forming a secondary valve in said secondary liquid passage in a manner that said primary valve is open only when said secondary valve is closed,

resilient means associated with said rod for biasing said primary valve in the closed position and said secondary valve in an open position, whereby the primary valve opens and the secondary valve closes when said primary outlet opening is opened to atmosphere as a result of a desire to obtain liquid flow therefrom,

a liquid pump having a discharge port communicating with the liquid receiving inlet of said valve assembly, and

an intake port of said pump connectable to receive liquid from a liquid source and said intake port connected within said housing to said secondary outlet opening, whereby a quantity of liquid circulates through said secondary liquid passage in a by pass path and through said pump when said secondary valve is open.

9. The liquid pumping assembly according to claim 8 wherein said secondary liquid passage includes at least one sharp turn of substantially 90 positioned therein, said rod one end being positioned to seal off said secondary liquid passage by movement thereinto at said sharp turn of the secondard liquid passage.

10. The liquid pumping assembly according to claim 8 wherein said flange is movable a distance along said primary liquid passage further than necessary to close off said passage, thereby permitting said resilient means to hold the flange in a position requiring movement thereof a distance before said secondary liquid passage is opened.

11. The liquid pumping assembly according to claim 10 which additionally comprises an internal combustion engine driving said pump, said internal combustion engine having a throttle, and means operably connected between said engine throttle and said rod in a manner to hold the maximum speed of said engine at a minimum when said primary valve is in its closed position and the secondary valve in the open position.

12. A liquid pumping assembly, comprising:

a liquid pump having intake and outlet ports,

means adapting said intake port for drawing liquid from a liquid reservoir,

a discharge liquid path in liquid communication between the discharge port of said pump and an outlet for controllably discharging liquid therefrom,

a bypass liquid path in liquid communication between the outlet of said pump to the intake of said pump, said bypass liquid path being established without going through a liquid reservoir,

a valve positioned within said discharge liquid path and operable between positions opening and closing said discharge path to liquid flow,

a valve positioned within said bypass liquid path and operable between positions opening and closing said bypass path to liquid flow, and

means interconnecting said discharge and bypass valves for moving them together in a manner that when one of said valves initially closes off its associated liquid path the other valve is simultaneously opening up its associated liquid path, thereby causing simultaneous liquid pressure changes in the liquid paths that promote fast movement of said valves.

13. The liquid pumping assembly according to claim 12 wherein each of the discharge and bypass liquid paths contains a sharp substantially right angle turn, each of said discharge and bypass liquid path valves movable between their opened and closed positions in a direction of one of the legs of their respective right angle liquid path sections, each of said valves closing off their respective liquid paths when moved into said one leg of their associated right angle section and opening said liquid path when the valve is moved out of said one leg.

14. The liquid pump assembly according to claim 12 which additionally comprises:

an output control valve for selectively opening or closing said outlet to liquid flow, and

resilient means normally biasing said discharge path valve to its closed position and said bypass path valve to its open position, the spring constant of said resilient means being of a low magnitude so that said discharge path valve quickly moves to its open position when said output valve is opened to permit liquid flow through said outlet. 

1. A liquid pumping assembly, comprising: a pump having intake and discharge ports, means adapting said intake port for drawing liquid from a liquid source, a discharge liquid path in fluid communication with the discharge port of said pump and with an outlet adapted for connEction of a liquid discharge hose, said discharge path including a valve operable between open and closed positions, a bypass liquid path in fluid communication from the discharge port of said pump to its intake port, said bypass path including a bypass valve operable between open and closed positions, mechanical means connecting said discharge and bypass valves for operating said valves as one unit, said discharge valve being open only while said bypass valve is closed, and, conversely, said discharge valve being closed only while said bypass valve is open, said mechanical operating means additionally controlling the discharge and bypass valves in a manner that when said discharge valve is initially opened said bypass valve is simultaneously closed, thereby to create a rapid liquid pressure increase in the liquid discharge path that quickly drives the discharge valve fully open.
 2. A liquid pumping assembly according to claim 1 which additionally comprises means associated with said mechanical connecting means for resilient biasing said discharge valve to a closed position and thus to bias said bypass valve to an open position.
 3. A liquid pumping assembly according to claim 2 which additionally comprises a liquid hose attached to said discharge outlet, and a valve installed on said hose that is operable between open and closed positions, whereby opening said hose valve to the atmosphere causes said discharge valve to move to its open position while the bypass valve moves to its closed position.
 4. A liquid pumping assembly according to claim 1 wherein said mechanical connecting means includes a rod extending between said liquid discharge path and said liquid bypass path, one end of said rod located within the bypass path forming said bypass valve and an enlarged flange surrounding said rod within said discharge liquid path forming said discharge valve.
 5. A liquid pumping assembly according to claim 1 which additionally comprises a motor operably connected for driving said pump, said motor having a speed control regulator that is operably connected with said mechanical connecting means in a manner to drive said motor at a low speed when said bypass valve is in an open position.
 6. A liquid pumping assembly according to claim 1 wherein said bypass liquid path includes means for controlling the size of said passage, thereby to permit control of liquid pressure against said discharge valve when in its closed position, whereby the speed of response of said valve moving to its open position may be controlled.
 7. A liquid pumping assembly according to claim 3 wherein said bypass liquid path includes a normally closed check valve which opens upon fluid pressure therein reaching a certain threshold value above normal atmospheric pressure, whereby pump priming is facilitated.
 8. A liquid pumping assembly, comprising: a housing, a liquid receiving inlet to said housing, a primary liquid passage within said housing forming at least one sharp turn of substantially 90* between said liquid inlet and a primary liquid outlet opening, a flange the size of said primary liquid passage and attached to a rod having a diameter significantly less than the size of said primary liquid passage for moving with said flange between extreme positions of closing said primary liquid passage by engaging all sides thereof and opening said primary liquid passage by moving to a position in said substantially right angle turn that allows fluid to travel along said primary liquid passage around said turn, a secondary liquid passage within said housing and in fluid communication with said liquid receiving inlet for discharging liquid through a secondary opening, said rod extending out of said primary liquid passage through a liquid-tight opening therewith, one end of said rod forming a secondary valve in said secondary liquid passage in a manner that said primary valve is open only when said secondary valve is closed, resilient Means associated with said rod for biasing said primary valve in the closed position and said secondary valve in an open position, whereby the primary valve opens and the secondary valve closes when said primary outlet opening is opened to atmosphere as a result of a desire to obtain liquid flow therefrom, a liquid pump having a discharge port communicating with the liquid receiving inlet of said valve assembly, and an intake port of said pump connectable to receive liquid from a liquid source and said intake port connected within said housing to said secondary outlet opening, whereby a quantity of liquid circulates through said secondary liquid passage in a bypass path and through said pump when said secondary valve is open.
 9. The liquid pumping assembly according to claim 8 wherein said secondary liquid passage includes at least one sharp turn of substantially 90* positioned therein, said rod one end being positioned to seal off said secondary liquid passage by movement thereinto at said sharp turn of the secondard liquid passage.
 10. The liquid pumping assembly according to claim 8 wherein said flange is movable a distance along said primary liquid passage further than necessary to close off said passage, thereby permitting said resilient means to hold the flange in a position requiring movement thereof a distance before said secondary liquid passage is opened.
 11. The liquid pumping assembly according to claim 10 which additionally comprises an internal combustion engine driving said pump, said internal combustion engine having a throttle, and means operably connected between said engine throttle and said rod in a manner to hold the maximum speed of said engine at a minimum when said primary valve is in its closed position and the secondary valve in the open position.
 12. A liquid pumping assembly, comprising: a liquid pump having intake and outlet ports, means adapting said intake port for drawing liquid from a liquid reservoir, a discharge liquid path in liquid communication between the discharge port of said pump and an outlet for controllably discharging liquid therefrom, a bypass liquid path in liquid communication between the outlet of said pump to the intake of said pump, said bypass liquid path being established without going through a liquid reservoir, a valve positioned within said discharge liquid path and operable between positions opening and closing said discharge path to liquid flow, a valve positioned within said bypass liquid path and operable between positions opening and closing said bypass path to liquid flow, and means interconnecting said discharge and bypass valves for moving them together in a manner that when one of said valves initially closes off its associated liquid path the other valve is simultaneously opening up its associated liquid path, thereby causing simultaneous liquid pressure changes in the liquid paths that promote fast movement of said valves.
 13. The liquid pumping assembly according to claim 12 wherein each of the discharge and bypass liquid paths contains a sharp substantially right angle turn, each of said discharge and bypass liquid path valves movable between their opened and closed positions in a direction of one of the legs of their respective right angle liquid path sections, each of said valves closing off their respective liquid paths when moved into said one leg of their associated right angle section and opening said liquid path when the valve is moved out of said one leg.
 14. The liquid pump assembly according to claim 12 which additionally comprises: an output control valve for selectively opening or closing said outlet to liquid flow, and resilient means normally biasing said discharge path valve to its closed position and said bypass path valve to its open position, the spring constant of said resilient means being of a low magnitude so that said discharge path valve quickly moves to its open position when said output valve is opened To permit liquid flow through said outlet. 